190709 贪婪算法练习

变形虫碰撞(点击可以跳转)

import java.text.DecimalFormat;
import java.util.Arrays;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        //读取键盘输入
        Scanner scan = new Scanner(System.in);
        int num = scan.nextInt();
        double[] weight = new double[num];
        for(int i=0;i<num;i++){
            weight[i] = scan.nextDouble();
        }

        //小到大排序
        Arrays.sort(weight);
        double SumWeight=weight[weight.length-1];

        //计算几何平均值
        for(int i = num-1;i>0;i--){
            double sqrt = Math.sqrt(SumWeight*weight[i-1]);
            SumWeight=2 * sqrt;
        }
        
        //格式化输出
        String parten = "#0.000";
        DecimalFormat decimal = new DecimalFormat(parten);
        String reweight = decimal.format(SumWeight);
        System.out.println(reweight);
    }
}

电话号码减法游戏

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int length = scan.nextInt();
        int num8 = 0;
        int numOther = 0;

        String TelPhoNum = scan.next().substring(0,length-10);
        char[] charTPN = TelPhoNum.toCharArray();
        for (char a: charTPN) {
            String n = a+"";
            int b = Integer.parseInt(n);
            if(b==8){
                num8++;
            }else{
                numOther++;
            }
        }

        if(num8>numOther){
            System.out.println("Yes");
        }else{
            System.out.println("No");
        }
    }
}

农场主安排奶牛工作

import java.util.ArrayList;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int cowNumber = scan.nextInt();
        int end=scan.nextInt();

        ArrayList<Cow> cow = new ArrayList<Cow>(cowNumber);

        for(int i=0;i<cowNumber;i++){
            int a = scan.nextInt();
            int b = scan.nextInt();
            Cow newcow = new Cow(a,b);
            cow.add(newcow);
        }


        int workCowNum=0;
        int worktime=0;
        int workstart = cow.get(0).start;
        int workend = cow.get(0).end;
        boolean iswork=false;
        boolean isend=false;
        for (int i=0;i<cow.size();i++){
            for(int j=i;j<cow.size();j++){
                if(cow.get(j).end>=end){
                    i=j;
                    iswork = true;
                    isend = true;
                    break;
                }
                if(workstart<=cow.get(j).start&&workend>=cow.get(j).end){
                    if(worktime<=cow.get(j).end-workend) {
                        iswork=true;
                        i=j;
                    }
                }
            }

            if(iswork){
                workstart = workend;
                workend = cow.get(i).end;
                worktime = cow.get(i).end - workend;
                workCowNum++;
                iswork = false;
            }

            if(isend){
                break;
            }
        }

        System.out.println(workCowNum+1);
    }
}

class Cow{
    int start;
    int end;
    public Cow(int a,int b){
        this.start = a;
        this.end = b;
    }
}